It is known that halides of phosphorus are able to react with primary and secondary amines, thereby producing amides of the various acids of phosphorus. For instance, as long ago as 1898, Michaelis and Kaehner in Ber., 31 (1898), pp 1040-1047 described the reaction of piperidine and tetrahydroquinoline with phenyl phosphorous dichloride to form the corresponding bis-piperidide and bis-tetrahydroquinolide. These compounds could be converted into the corresponding amides of phosphonic and phosphonothionic acid.
Subsequent work has described the reaction of phosphorus halides or oxyhalides with a variety of amines, and hydrazine. Attention is to be directed in this connection, for instance, to U.S. Pat. Nos. 2,906,770; 3,107,231; 3,260,702 and 3,649,594. Little attention, however, has been paid to the use of piperazine or substituted piperazines as amine reactants.
A paper by Bello et al in Macromolecules, 3 (1970) pp 98-100 describes the reaction of dimethylphosphoramidic dichloride (CH.sub.3).sub.2 --N--POCl.sub.2 with an excess of piperazine to give phosphoric dimethylamido bispiperazide. ##STR1##
This compound was subsequently reacted with oxalyl dichloride or piperzine--1,4--dicarbonyl chloride to give polymers. Polymers with alternating piperazine and (CH.sub.3).sub.2 N--PO: groups were obtained by using an excess of the phosphorus halide.
The object of the present invention is the preparation of novel phosphorus compounds containing piperazine rings. Other objects of the invention are to produce novel phosphorus compounds useful as components of petroleum compositions. Further objects will be apparent to those skilled in the art.